Problems Uploading to Gallery

LionFlyer · 05-21-2004

I noticed something today which may affect others on this fourm who upload images to the galleries. I was using a 45Mb internet connection. After work today I lingered in my office to upload some photos to this site. But part way through the uploads stalled out. Hung. I tryed reducing the file size with the same results. I used a network sniffer to capture my connection so I could see why this was happening. What I discovered was that the TCP transport window size from this site, while starting large, (> 25K) grew ever smaller with each packet. Until the window size from this sight reached zero. That is when the upload stopped. As it should have. But it never recovered even after several minutes. I packed up the laptop I was using and brought it home where I have a "broadband" (Yah right) cable connection. Same computer, same files, slower connection and the files all made it fine. I am greatful for the use of this nice site. But there is a problem, a bug, or something in the transport layer. I know not many, maybe I am the first one, will step in this, but it is there none the less. I just want to save anyone else who may be wondering why their uploads hang from spinning their wheels.

Harvey Platter · 06-14-2004

This one's been around for a long time and I'm wracking my brains to remember what the fix is. We had this at a big Telco I worked at when we were putting big files across a T2 line. Some of the files were 4-500GB (yes, you read right, Gigabytes) and they would shoot across at high speed to begin with then slow down and down as the window shrank.

Like I say, I can't remember the exact fix but I know we had to do something fairly drastic to the FTP daemon on the receiving machine. Actually, thinking about it, I think we got a fix from IBM. I don't think we had to do anything on the transmitting machine because it's a receiver side failure.

LionFlyer · 06-16-2004

Harvey, thanks for your thoughts. I figured it is a rate thing. I added some rate shaping to my internet gateway for this site. When I limit the mean upload rate, I have success. Right now my upload rate to RFF is 384K. ( aprox: T1 * 1/4)